If your home currently has single pane windows, your air conditioner must work harder to cool hot air from sunny windows. Switch to Energy Star-qualified windows to give both your air conditioner and energy bill a break.
Replace your single pane windows with double-pane high performance glass, such as low-e or other selective coatings to reduce heat gain. To further protect your home from heat, install white shades, blinds, or curtains to reflect heat away from the house, and close those curtains on south and west facing windows during the day.
When shopping for windows, look for the Energy Star label. As an added bonus, your local energy company may offer rebates or other incentives for window replacement.
Installing energy efficient windows will pay off in the long run, in energy bill savings, and it also brings the immediate benefits of comfort, improved aesthetics and functionality.